Hiromasa Hirakawa

Microwave Spectrum of Formaldehyde I. K -type Doubling Spectra

Microwave spectral lines for the direct transitions between the K -type doublets were measured from 3 kMc to 40 kMc for H 2 CO and for its isotopically substituted molecules HDCO, H 2 C 13 O and H 2 CO 18 . The observed spectra and the previously reported data for H 2 CO were analyzed by a digital computer by the use of Kivelson and Wilsons method for the centrifugal distortion correction. The asymmetry parameter b and B – C were obtained for each isotopic species as follows:

Microwave Zeeman Effect of Formaldehyde

Zeeman effects in the absorption spectra of formaldehyde H 2 CO, HDCO, and D 2 CO were studied in microwave region with magnetic field of 1500∼300 oersteds. The effective g -values in several rotational states and the elements of g -tensor g a a , g b b , and g c c of these molecules were determined. Dependences of the effective g -values on the rotational quantum numbers J , τ were consistent among these isotopically substituted molecules. The components of the g -tensors of these molecules have been found to be g a a =2.86±0.04 for H 2 CO, 2.00±0.05 for HDCO, and 1.46±0.05 for D 2 CO. They are extraordinarily large compared to those of other molecules already known. A brief qualitative interpretation is given.

Dependence of Quadrupole Coupling Constant on the Vibrational State in ICN Molecule

The microware spectrum of the hyperfine components of the J =1←0 and J =2←1 rotational transitions of ICN molecule has been measured and the dependence of quadrupole coupling constant on the vibrational state was found. The values of ( e q Q ) I for each vibrational state are as follows:

Microwave Spectrum of BrCN and Dependence of Quadrupole Coupling Constant on the Vibrational State

The hyperfine structure of the J=1←0 and J=2←1 rotational transitions of BrCN has been measured. The values of eqQ(Br 79 ) and eqQ(Br 81 ) for each vibrational state were obtained as follows.

Dispersion of Gravitational Waves

The equation of the vibrational motion of an isotropic elastic body in the field of gravitational wave is obtained. Using the eigenfunction expansion of the motion, the dispersion equation of the gravitational wave in a medium composed of dispersed elastic bodies is presented.

Dynamic Polarization of Deuterons in d-LMN Crystal

Dynamic polarization of deuterons in a single crystal of La 2 Mg 3 (NO 3 ) 12 ·24D 2 O doped with Nd ions has been measured at 1.4 K with pumping by 35 GHz microwave. The 48 hfs components of DMR are identified with the sites of deuterons, and the enhancement factors are determined for each of them. The dependence of the polarization on the magnetic field agrees with the calculation based on the differential solid state effect. A possible effect of the quadrupole relaxation is noted.